The installation contractor's sewer work – from pipe laying to authorization

When you dig a utility trench or sink a well you are working with some of the most invisible but also most regulated things in all construction: the sewer. Errors in a drainage system are rarely noticed immediately – they show up only when the basement gets wet or when wastewater seeps out where it must not. That is why sewer work is surrounded by clear rules which you as a construction technician must know and work within.

§Why does sewer work require authorisation?

Work with drainage installations in the ground may only be performed by a company authorized by the Danish Safety Authority as a sewer-master business. This includes, among other things, establishing and repairing sewer pipes in the ground, replacing or installing new wells and connection to the main sewer. As an apprentice or journeyman, you are not personally responsible, but you perform the plumbing work as an executing employee in the authorized company — in accordance with the Danish Safety Authority's rules, as also stated in the education's regulations. The authorization scheme exists because errors in drainage systems can pollute groundwater and harm people's health, and because it is expensive and disruptive to correct work that has already been buried.

§DS 432 – the standard that governs the work

The technical basis for drainage work is the standard DS 432 Norm for Drainage Installations which has been updated several times — most recently in a new edition from 2020 partly to follow changed requirements in the Building Regulations. DS 432 sets requirements for sizing materials gradient and execution both for installations in buildings and for drainage systems in the ground within the property boundary. On top of the standard comes the Building Regulations' drainage provisions and the individual municipality's wastewater plan which specifies how rain and wastewater should be handled in the specific area you work in.

• 01Establishment and repair of sewer pipes in the ground
• 02Replacement or new installation of wells and inspection wells.
• 03Connection to main sewer
• 04Establishment of backwater valve, drain, and perimeter drain
• 05Mini purification plant and infiltration system
• 06Separation of rain and wastewater and rat barriers in pipes

§From large pipes to infiltration and separators

The education sets concrete requirements for what you must be able to do technically: you must be able to install large pipes and wells considering the lifting equipment and materials the task requires, and you must be able to prepare drawings and perform sewer installations, infiltration, pump, and separator systems, and sewering in agriculture—all in accordance with the Danish Safety Authority's practical education requirements for the responsible party in an authorized sewer master business. A separator system, for example, holds back oil or grease before water is sent further, while an infiltration system is used where there is no public sewer and wastewater must instead be treated locally and infiltrate into the ground.

§Climate adaptation and separate sewerage

Pipe stress

§The path to becoming a sewage master

Many construction engineers use the sewage trade as a clear career path. With experience and relevant further training, you can aim to become the responsible party in an authorized sewer company. This requires you to pass a sewer master exam approved by the Danish Safety Administration, where you document both practical and theoretical knowledge of standards, regulations and execution. It's a solid springboard for you who want more responsibility — and maybe one day have your own authorization.

“What lies in the ground you need to be able to stand by for decades — without anyone ever digging it up again.”